// JavaScript Document

 function $$(id)  
{  
  return document.getElementById(id);  
}  
 var LoginUI = !!window.LoginUI || {};  

 LoginUI.getViewportWidth = function(){  
    var width=0;  
     if(document.documentElement && document.documentElement.clientWidth){  
     width=document.documentElement.clientWidth;}  

     else if(document.body && document.body.clientWidth){  
    width=document.body.clientWidth;}  

     else if(window.innerWidth){  
    width=window.innerWidth-18;}  
    return width;  
 }  

 LoginUI.getViewportHeight = function() {  
     var height=0;  
     if(window.innerHeight){  
     height=window.innerHeight-18;}  

    else if(document.documentElement&&document.documentElement.clientHeight){  
    height=document.documentElement.clientHeight;}  

     else if(document.body&&document.body.clientHeight){  
     height=document.body.clientHeight;}  
     return height;  
 }  

 LoginUI.getViewportScrollX = function(){  
    var scrollX=0;  

    if(document.documentElement&&document.documentElement.scrollLeft){  
     scrollX=document.documentElement.scrollLeft;}  

    else if(document.body&&document.body.scrollLeft){  
     scrollX=document.body.scrollLeft;}  

    else if(window.pageXOffset){  
     scrollX=window.pageXOffset;}  

    else if(window.scrollX){  
     scrollX=window.scrollX;}  
    return scrollX;  
 }  

 LoginUI.getViewportScrollY=function() {  
     var scrollY=0;  
     if(document.documentElement&&document.documentElement.scrollTop){  
     scrollY=document.documentElement.scrollTop;}  

     else if(document.body&&document.body.scrollTop){  
   	 scrollY=document.body.scrollTop;}  

     else if(window.pageYOffset){  
	 scrollY=window.pageYOffset;}  

     else if(window.scrollY){  
	 scrollY=window.scrollY;}  
     return scrollY;  
 }  

 function scrollMsgTip()  //固定头部NAV
 {  
    var t = LoginUI.getViewportScrollY();  
    $$("msgtip").style.top = t + "px";
    $$("msgtip").style.left = LoginUI.getViewportScrollX() + "px";  
 }